#usr/bin/env python3
#-*- coding:utf8 -*-
#with open(r"C:\Users\Administrator\Desktop\test.txt",'r') as f:
#    print(f.read(7))
#f.close()
from tkinter import *
import tkinter.messagebox as messagebox

class Application(Frame):
    def __init__(self, master=None):
        Frame.__init__(self, master)
        self.pack()
        self.createWidgets()

    def createWidgets(self):
        self.nameInput = Entry(self)
        self.nameInput.pack()
        self.alertButton = Button(self, text='Hello', command=self.hello)
        self.alertButton.pack()

    def hello(self):
        name = self.nameInput.get() or 'world'
        messagebox.showinfo('Message', 'Hello, %s' % name)

app = Application()
# 设置窗口标题:
app.master.title('Hello World')
# 主消息循环:
app.mainloop()

def findnum(x,n,m):
    s = 0
    for i in range(1,n+1):
        if x//i >= m:
            s = s+m
        else:
            s = s+x//i
    return s
    pass

if __name__=='__main__':
    n,m,k = raw_input().split()
    n,m,k = map(int,[n,m,k])
    low = 1
    hight = n*m
    while (low<=hight):
        middle = (low+hight)//2
        par = findnum(middle,n,m)
        if par < k:
            low = middle + 1
        else:
            hight = middle - 1
    print(low)